Testing Flintlock Speed and Consistancy

[dlemaster]

Recently I was reading an paper by Larry Pletcher in the Journal of Historical Armsmaking Technology Vol.4 titled "A Study of Lock Timing."
Mr. Pletcher was setting up a test to compare lock speeds on 4 original flintlocks.
In setting up the parameters for the test he used a properly tuned large Siler flintlock as a control. After the set up and testing using the Siler lock he came to this conclusion "After finishing this test and studying the data, I concluded that perhaps the longer the frizzen scrape, the more consistent the lock. The quality of the spark, at least in the test lock, was the most consistent when the scrape was kept as long as possible. Variations in time were also smaller with longer frizzen scrapes. (The easiest way to obtain a longer frizzen scrape is by placing the flint bevel down which can increase the frizzen scrape by as much as 40% in some locks)."
Two of the original locks tested were smaller late period English flintlocks, both of which Mr. Pletcher noted had very stiff springs, recorded the fastest lock times. After testing the original locks Mr. Pletcher had this to say "Perhaps a higher velocity of the flint edge is more important than the theory mentioned earlier - that the length of the frizzen scrape was most important. The testing seems to support this theory. The Siler, which was measureably slower mechanically, had weaker springs and a frizzen scrape as long as the original locks."
He felt that the earlier lock makers were more concerned about consistancy and reliability than lock speed. This would explain the use of heavy springs and long throws on large early locks. But by the late flint period lock makers were trending toward smaller locks possibly to lighten moving parts increasing the speed of the frizzen scrape and maybe evidence that they were more concerned with increasing the speed of their locks.

The information can be found in the Journal of Historical Armsmaking Technoloy Vol.4 pages 61 through 101 published by the National Muzzleloading Rifle Association, January 1991

The paper also has interesting data comparing the use of agates vs chipped flints and various granulations of powder used as a priming charge. It also has a great series of high speed photographs of an original English lock by Staudenmeyer as it fires. It is a great read for any flint lock shooter.

Regards, Dave

 

[roundball]

The paper also has interesting data comparing the use of agates vs chipped flints and various granulations of powder used as a priming charge. It also has a great series of high speed photographs of an original English lock by Staudenmeyer as it fires. It is a great read for any flint lock shooter.
Regards, Dave

Dave, sounds interesting...do you know if this is available on the web or only in hard print?

 

[mike alexandre]

and I was going to ask the same question?

 

[Old Ironsights]

Goodsearch is your friend.

I found this:[url] http://members.aol.com/illinewek/faqs/locktime.htm[/url]

FLINTLOCK TIMING

Larry Pletcher

Indiana
Since 1988 I have had the opportunity to measure the ignition time on a number of different flintlocks. The locks varied from superb original locks to modern day reproduction locks. Some were in mint condition, while others were somewhat used.

The purpose in timing these locks was to learn as much as possible about how fast locks really are and to find out what characteristics make a lock fast. Most of us have heard comments about a lock being particularly fast or slow, but these comments are based on human perception rather than scientific measurement. I hoped to shed at least some light on this topic.

In conversations with flintlock makers and shooters at Friendship, I found that many people were interested in a lock timing project. I was given the chance to time a few locks on the porch at Gunmakers Hall during the 1988 Fall Shoot. Gary Brumfield, Master of the Williamsburg Gun Shop, was the inspiration behind this....

 

[Old Ironsights]

BTW:

"Bevel Up or Bevel Down" I understand the concept, but not the definition.

I am probably wrong? but when discussing the bevel up/down are you talking about tangent to face or along the plane?

i.e. =/ (bevel down tangent) =\ (bevel up tangent)

OR

=\ (bevel down plane) =/ (bevel up plane)

From the sourced article, (and how I have always thunk it) I would assume he is talking about Bevel Down Tangent since that would allow the longest scrape time.

 

[TANSTAAFL]

My requisites for a lock are quite simple, with all other things being equal, does it go off when it should.

 

[Stumpkiller]

Your first one.

This is bevel down.

 

[paulvallandigham]

Bevel down puts the edge of the flint the highest on the frizzen and gives the longest scraping of the face of the frizzen.

Bevel up means the bevel is at an angle to the plane of the bottom jaw of the cock, while the bottom surface of the flint, leading in a straight plane to the edge sits on top of this bottom jaw plane, and parallels it. This position give a shorter stroke on the frizzen face. As long as the flint is set so that it strikes the frizzen more than half way up the height of the frizzen measured from the heel of the " L ", the frizzen will pop open properly when it is struck.


For future testing, it is much more instructive not to prime the pan when you do this test with photographic equipment. Of course, a separate test is needed to reassure us that the sparks will actually light the priming charge. But, after that is established, it does not have to be repeated with each test. In fact, you learn much more about ignition when you can see the individual sparks and where they go when they fall to the pan.

 

[Bill Bryan]

I have heard the discussion that the amount of time for a flintlock to function is so small that it is not noticable. However, I like many other flintlock shooters often notice a delay. I don't think that it is my imagination.
I've recently started inserting the vent pick into the vent hole before loading. This has improved the speed more than anything else I've tried. :hmm:

 

[ronrryan]

Bill, has inserting the vent pick BEFORE loading icreased speed of ignition more than (or about the same) as inserting the pick AFTER loading? I'd be thankful to know your experience, Ron in Fla

 

[mike alexandre]

Excellant, thankyou

 

[paulvallandigham]

Bill: This is about lock speed, and not ignition speed. YOu have found out the other great truth about getting quick ignition, and that is that if you have an airspace beyond the touch hole for the flash and its heat to enter the main powder charge, ignition speed becomes almost instantaneous. Some put a pick in the touch hole before loading the main charge, and PRB, while others, like you and me, use our vent pick to poke a hole in the main charge after the charge is loaded.

There are three more things that you can do to aid quick ignition of the main charge:

1. Bank your powder charge away from the touchhole in the priming pan to leave an airspace next to, and under, the touchhole.

2. Use the coarser 2Fg rather than 3Fg powder, so that you have more oxygen interspersed between granules of powder in the barrel. This extra oxygen allows the powder to ignite quicker, and pressure to rise faster.

3. Load your PRB, or conical, to a mark, rather than attempting to compact your powder charge. Tests show a slightly lower velocity, which can be easily corrected by adding a few more grains of powder to your load, but more important, the Standard Deviation in Velocity( SDV) is much lower for flintlocks when the powder is not crushed, or compacted, as we would do in a percussion gun.

I note the reference to percussion guns as most of us start in BP shooting with a cap and ball gun, and only get smarter after we have hung around old rocklockers on the range. In a percussion gun, you get lower SDV if you compact the powder.

Since I discovered that fact, I have been telling every Flintlock shooter I meet that the two systems of shooting black powder are truly different, and almost opposite in how you get your best performance. For instance, I would not hesitate to recommend using 3Fg powder in virtually all percussion guns. In Flintlock guns, I have to recommend 2Fg powder in all but the smallest of calibers. ( .31-.36), based on test results. I do think flintlocks shoot better if you make sure you seal the gases behind the ball, and that either a overpowder wad, or a filler does this better than any cloth patch, unless you use Teflon patches and an oversized ball that you hammer into the barrel. I don't consider teflon to be cloth, but I thought I would note it here to avoid someone jumping in with that observation. Most of the teflon-and-hammer shooters are using percussion guns, anyway.

 

[davy]

Good stuff Paul, I shoot both Flint and Perc, and will try some of these idears! I learn sumthin new everday .. whether I need it or not! :thumbsup:

Davy

 

[dlemaster]

Paul
One other thing this artical mentioned, that I found interesting was that 60% of the ignition time occured after the mechanical function had ended.

Mr. Pletcher noted the very stiff springs on the late English locks but the Staudenmeyer lock I mentioned was also tested with a set of weaker springs supplied by its owner. There was an increase in the lock time but the standard deviation did remain rather small.

One of the complaints I heard about Siler locks while I worked as an apprentice back in the late 70's was that the throw was too short. It was said that Bud Siler made the locks with a relatively short throw as a concession to target shooters who felt that a longer throw or stronger springs might jar a rifle too much for good target work. Even with what some considered these short comings most felt it was probably the best lock off the shelf and commercially available at that time. I have noted that both of the locks I use the most now, a Chambers Christian Springs and a Caywood Wilson's, both have stronger springs and longer throws. I prefer them both to the early Siler lock on the rifle I made in the early 80's.

Regards, Dave

 

[dlemaster]

Roundball and justmike
As far as I know it is only available in print. I bought my copy at Friendship last year. I think that all 5 volumes are out of print and as I understand it there is some kind of glitch in the rights that keeps them from being republished. Which is a shame as there is a lot of very good and valuable information in them.

Regards, Dave

 

[flintriflesmith]

There were five volumes of JHAT and enough were printed that they frequently turn up on the used book web sites. Volume 2 and 5 are the hardest to find. Volume I was the most popular seller but it was reprinted 3 time for a total of about 5000 copies.

The reason they have not been reprinted is very complex but to summarize it: a lot of the original art is no longer available and no one is completely convinced that there is enough of a market to justify reprinting the old volumes when the same funds could be spent continuing the series with fresh new material.

Gary, Editor of JHAT

 

[dlemaster]

Thanks Gary. I had heard several reasons for them not being republished but your reasons make sense.
I just bought the vol.1 copy on ebay and Tom S. is trying to help me locate vols 2,3 and 5. I have read all 5 volumes but I would really like to have them for my own library.

Just one other question. Are there any plans for future volumes?

Regards, Dave

 

[flintriflesmith]

Just one other question. Are there any plans for future volumes?

Regards, Dave

We will be discussing that subject at the Publications Committee meeting next month. It came up a few years ago and was approved in principle but no details were available on which to make a decision.

I am very much in favor of starting another series but funding it will be an issue. Some folks have suggested looking for grant money.

When we are trying to get some of the very best researchers/builders to write scholarly articles, there is a lot more than just printing costs involved. Good photography is also expensive-- I think Wallace and Dave Harvey paid more for the photos they used in the Sheetz rifle article (Vol. 5) than they was paid for writing it.

 

[strask]

Hi Guys i am a newbie here so forgive me if I am asking this in the wrong place. I just started shooting flintlocks last year and I enjoy it more every day. My question is does powder mfg. ie goex,swiss.... make any difference for ignition time in ref to airspace etc.

Thanks,

Digger Scott

 

[paulvallandigham]

Not a measurable difference. You will get more changes in speed based on the size of powder you use to prime, but, the difference is measured in millionths of a second, and you really can't hear the difference, there, either. Regardless of the brand you choose to shoot, it probably serves you well to sift the powder to get a more uniform powder to load for accuracy. People complain about FFFg powder being tempermental, or " spikey". I really believe that this occurs because many cans of FFFg have more 4Fg in them than 3Fg! So, find a couple of buddies and go together to invest in a powder sifter, and sift all your cans of powder. I think your 3fg powder, regardless of manufacturer, will behave more predictably when trying to shoot small groups on the range. I am not so sure the average shooter can take full advantage of the additional consistency and accuracy that flows from using sifted powder when shooting off-hand in hunting conditions, so you will hear different comments about the value of sifting powder. Swiss is much more expensive to buy than Goex, here, so I have a lot of trouble justifying spending the extra money. It comes in plastic bottles, rather than metal containers, as does most Goex, and that may affect how much the powder is broken down to small grain sizes in transit. I still think its worth sifting your powder so you know what you have, before you put a load of powder in your barrel.